a) Field of the Invention
The invention relate to an opthalmological examination device and a method for its use.
b) Description of the Related Art
EP 369 415 and EP 562 742 describe a "direct retinal scan display" as an alternative to optical displays such as monitors, wherein only very low outputs (not more than 20 microwatts) are required owing to direct "writing" of the image information on the fundus oculi of the observer. Video information (e.g., RGY signals) is modulated on one or more laser beams and these laser beams are deflected in the x-direction and y-direction by means of a scanner which can comprise piezocrystals, for example, and reflected in the observer's eye via a reflecting plane surface. Variable optics serve to focus the beams on the retina. The system can be used monocularly or binocularly.
U.S. Pat. No. 5,467,104 and WO 94/09472 describe a "virtual retinal display" (VRD) with high resolution and color representation. Light from a laser or a LED is modulated corresponding to video information and is projected directly onto the retina by means of a microscanner and projection optics. The reflecting element for reflecting in can be a splitter mirror, so that the projected image is superimposed on the surroundings.
A "pupil tracking system" monitors the position of the eyes and shifts the projection direction so as always to strike the pupil of the observer. A field of 140.degree. can be presented to the observer.
In many ophthalmological applications (e.g., slit lamp, fundus camera, laser ophthalmoscope), the physician examines the various parts of the patient's eye (cornea, iris, lens, vitreous body, retina, etc.) via an optical viewer and/or a monitor. In the case of the slit lamp, a stereo microscope with a viewer is used to observe the slit image, wherein the reflection of a partial image in a video camera and display thereof on a monitor is known.
In fundus cameras, the adjustment of the fundus image is normally observed via an ocular or a monitor.
Apart from the uncomfortable body posture of the physician due to the known arrangements, it is disadvantageous that it is not possible for the physician to simultaneously see the whole patient as well as the eye, or the whole eye as well as the affected portions of the eye. A mechanically and optically complex component group is required to carry out observation. When observing the monitor, the stereo display is limited and the resolution is reduced. Stereo viewing goggles working on the shutter principle (alternating display of the image for the right and left eye) cannot provide an image free of flickering due to the system (100 Hz television technology).
Above all, when a large number of patients are seen daily, but also during a prolonged individual examination, the act of monocular viewing is very tedious for the treating physician.